Just wanted to recount an incident that happened to me about a month ago. For the last 4 years I noticed 5 rather large and noticeable spots forming on my forehead. The largest was just a little larger than a normal pencil eraser. Being mostly Pogue instead of Heinz 57 like a lot of Americans, I have very light skin. I figured they were large freckles, or since I have passed the half century mark now, perhaps age spots.

But then two of my hiking buddies keep insisting that they were melanomas, even going into graphic details about how they would have to cut not only the melanomas out, but three inches around the melanomas and then replace the skin with skin from my butt. I would look like a freak for the next two years if I survived the ensuing lymph node cancer and I might actually be able to hike again some day if I was lucky.

Well my friends managed to scare the angels out of my nether regions, so I went to my doctor expecting the worse and getting in touch with my Catholic roots along the way and hoping I would make it to heaven so I could at least have a hooley with my Irish relatives once I got up there.

But no, it turned out they were not melanomas, but actually were big freckles or age spots which is what I thought in the first place. I normally don't put sun block on my forehead because it mixes with sweat, runs into my eyes and stings them. I hike mostly in the Sierra of Northern California where there is a lot of granite which reflects sun up under the brim of my hat thus causing the big freckle or age spots where I don't put the sun block. At least that was Dr. Saeed's theory. I told the Doc that I didn't like the spots in any case because people tell me I look like David Letterman and I would rather look like Colin Ferrell. He told me he wasn't a plastic surgeon, but that he could take care of the spots.

He left the room and came back 5 minutes later with a plastic cup with one of those long handled medical Q-tips with cotton only on one end. There was smoke coming out of the cup. Liquid nitrogen he said. He would apply it to the spots, and they should drop off in two weeks. I asked him if it would hurt. Not as much as cutting them off with a scalpel, which is what he would have to do if this didn't work. I said proceed Doctor, use as much of that stuff as you want. When the medical Q-tip saturated with liquid nitrogen hit my spots it sounded like bacon in a frying pan, but I didn't flinch because I was convinced I would look like Colin Ferrell in two weeks. Two weeks have passed and the spots did indeed drop off, but I still look like David Letterman. Dr. Saeed was right, I would need a plastic surgeon to look like Colin and that's not covered under my medical plan, but I do have one advantage over Letterman, my hair is only half grey and it's still all there.

Guys, the moral of the story is that as hikers and backpackers, we are out in the sun a lot, so wear wide brimmed hats and use sun screen, especially if you have Celtic skin that glows in the dark. A ball cap just won't do. As for my forehead, it's doing fine, but I still am not inclined to use sun block up there. I may have go pirate and start wearing a "Do Rag" or a Buff-- avast ye maties!

My grandmother is on the board of directors for U.S. Sailing. She's been indoctrinating her 11 grandchildren with sun protection for two decades. We are all afforded tilley hats and U.S. Sailing shirts with sleeves as often as she can.

One theory is that sunscreen blocks the UV rays that cause sunburn, but not skin cancer. Sunscreen may actually make skin cancer worse, because it inhibits tanning which gives you some protection, plus if you get burned, you will get out of sun but if you're protected against burn you'll stay out in sun longer and get more skin cancer causing exposure.

Wide brimmed hat, long sleeved shirt, long pants, avoid periods sun especially at high altitude or if you get reflection from water or snow, especially 3 hours before/after noon (standard time - 10 AM to 4 PM daylight saving time).

I've had five skin cancers carved off and while I'm a Celt who grew up in California, they didn't pop up until I unknowingly drank high arsenic water for a year. Then I got them all 2-3 years later. Basal cell cancers are almost always benign and slow growing whereas squamous cell are worse and melanomas even worse. By the time my outdoorsy cousin Gary was my age, he'd been dead for 12 years from a melanoma.

I've got a good derm guy locally, a national expert I go to see every few years, I know rather a lot of doctors (cause I sleep with one) and toxicologists (I'm an environmental engineer). A few thoughts:

Everyone talks about sunscreen but we're no longer sure how good an idea that is. Yes, it prevents sunburn. And vitamin D. It's very unclear about skin cancer. Hats - good. Long sleeves - good. The expert I see says, "Roof, hat, sunscreen." You can do "roof" even while outdoors. Stay in the shady spot on the beach. Stand behind the tree inside of in front of it, etc.

Some cancers seem to go by a "multi-hit" model. Genetics had to be tweaked (UV, cosmic ray, bad genes, toxic exposure) for a cell to rapidly grow. It had to be further tweaked to avoid programmed cell death. For me, perhaps, the sun may have mutated millions of cells. Then arsenic mutated thousands more in a different way. And perhaps the overlap was 5 cells that took off in a cancerous direction.

Still, we all have to die of something and if we stay home and do nothing, we'll either die of boredom or get depressed and shoot ourselves, so it's all a balancing act of risks and rewards.

In my youth, I didn't worry about being in the sun at all. But now that I'm older, I always hike in long sleeves, long pants, long-billed hat with neck shade and especially sun gloves. I don't like sunscreen because our skin absorbs the chemicals. I wouldn't put sunscreen in my mouth so I don't want to put it on my skin either.

I had a scare a year ago when my doctor found something on the top of my head. The dermatologist said it's either a mole or cancer and had to be removed and tested. Fortunately it was a benign mole. Also, fortunately they didn't have to "replace the skin with skin from my butt".

It's wise to get your skin checked regularly when you get older. Also, cover up well from a young age.

My Dermo Dr. recommends once a year checks if you've never had skin cancer and 6 month checks if you have had some.

So I see my Dermo Dr once a year. I almost always get something burned off but no cancer.

My wife goes in every 6 months and has had several cancerous items on her skin.

100% coverage with clothing is my strategy. My wife has relied on sun screen but is moving in my direction. She is currently biking across the US and is fully covered, including a broad brimmed hat under her helmet.

When the doctor calls you rather than sending an e-mail it's a bad sign. I had a cancerous melanoma sliced out of my face and it's not pleasant. Luckily it hadn't spread because this type of cancer is extremely deadly once it gets into your nodes. It really can't be treated.

So: I ski in the winter; backpack at altitude; swim; etc. Now I'm completely covered while outdoors and preach sun protection. The old "something's going to kill you so whatcha gonna do?" philosophy really comes up short when you're 52 and waiting to hear back from your lab results. Seriously, just wear the friggin hat. And sunscreen. And sun grubbies on your hands. The idea that sunscreen is going to give you skin cancer is ludicrous.Oh and you don't have to get burned before exposure can become dangerous.

Like Jeff above, I've had hunk hacked out of me after the Dr. personally called my house, office and cell to find me. When he said, "(w)ell can you come in this afternoon? We've made some time for you...", I got that Oh Damn Moment. In my case, it was a little smaller than the palm of my hand and 1/4" deep, to excise something the size of a BB on the surface. No skin-grafting to fix it, though.

I've also had numerous sunspots frozen off my face and left arm. Yes, I spent years driving with my arm out the window of the car, and most of my sunspots are also on the left side of my face.

Been there, done that, luckily mine was only basal cell. Just a hat was obviously not enough protection. So yes, do wear both protective clothing AND sunscreen. If you are worried about chemicals in sunscreens use sunblock (zinc, titanium oxides). There is some concern that oxybenzone and retinyl palmitate may be hormone disruptors and contribute to cancer, so avoid those if you are worried about that.

My nephew (age 40) had a melanoma removed last year, luckily it was the earliest stage and prognosis is excellent; but we all were freaked out again a couple of weeks ago when he had 3 new spots biopsied, luckily none were melanoma though one was pre-cancerous. He has always been an outdoors person and has a good tan (1/2 Japanese ancestry) so if you think your tan will protect you, guess again.

I had to get on his case after this latest biopsy about wearing UPF rated clothing; he was on his way to Hawaii with long-sleeved cotton shirts and a baseball cap, so he had virtually no protection other than sunscreen along. An early birthday present from me took care of the shirt situation, and his wife and I both gave him grief about finding a real hat for the trip.

Max: my doctor said that my cancerous spot "started" 25 years ago. That's when I used to lie out in the sun after doing laps. And of course high mountain sports; the sun at altitude just fries you. So yes, it seems to be a matter of accumulative exposure. No one in my family has this problem, so I don't seem to have high genetic risk.

I also came to notice how exposed I am to sun while driving. This includes my hands: almost 100% exposure during the day; and like Eric mentioned, the left side of my face, ears neck and arm. So now I wear a sun shirt and sun grubbies while driving the 5 hours to Tuolumne, etc.And sun shirt, spf pants, big hat and sun grubbies while hiking. Covered.

Sadly, a baseball cap just doesn't cut it. Just notice the next time you see someone wearing a ball cap how little it actually keeps the sun off his/her face.